Gary Flandro. Not sure if he was Italian or not (thought he was American).

I stand corrected: Gary Flandro is an American, would not presume to speculate on his ethnic background, not that it's anyone's business but his own.

Point still being, is there anyone out there actively seeking favorable trajectories/opportunities for the outer planets? I'm sure that there are lots of direct launch windows known, but thinking more of creative things like the Cassini/Galileo flight paths. They're long, but they work, and knowing about them would be a valuable planning tool.

My brain's bouncing off a statement made a couple pages back, rattling off categorizations of moon-designated missions one by one and came up with:

Io's a volcanologist's dream
Europa's a glaciologist/oceanologist's dream.
Ganymede's a glaciologist/geologist's dream
Callisto's a mortician's dream.

<evil grin... should't be so hard on poor old Callisto>

Thinks have changed since the Voyagers. There are tools now to search for viable trajectories and optimize them based on various constraints like delta-V at launch, launch windows, flight time, even stuff like minimum Venus flyby altitude. I don't think anyone designs trajectories for interplanetary probes on the basis of stumbling upon a good trajectory.

Thought so; in fact, seems as if I saw a recent paper on one such trajectory discovery for a main-belt asteroid tour.

What I'm really wondering is whether there is a concerted and organized effort by anybody to identify all such opportunities (within the realm of practicality, of course) between now and, say, 2100. For example, if we found a very favorable launch opportunity for Uranus in 2027, there would be twenty years available to begin planning, proposal submission, lobbying, etc.

The problem is what do you mean by "very favorable"? There are lots of things you might want to optimize. But I agree that for a given velocity leaving earth, the time to get to various planets would have a number of minima which should be searchable. Going to Mars is a bit simpler, has a minimum ever ~2 years.

And Titan has all of the above*.... plus it is an organic chemist's
dream, and a meteorologist's dream, etc. etc......

Plus you can actually put down instruments (thanks to atmosphere for
aerocapture, and entry/descent) to let you do in-situ chemistry, seismology,
soil mechanics, and lots of other good science you simply cant do affordably
at these other places.

You can OBSERVE all these Jovian bodies at varying degrees of detail. You can
actually EXPLORE Titan...

*ok - jury is still out on present-day cryovolcanism. Bet it's there tho..

As for the question about mission library, I don't think so (isolated design
cases get published in papers etc., but no library as such - since there are
competed mission lines like Discovery, NF etc., it would make little sense
to provide data for your competition...)

But it's a pretty straightforward situation - you get Jupiter gravity assists to
Saturn every 15 years or something (repeat the alignment, so one Jupiter
period is 10 years, right, but in that time Saturn goes around 1/3 orbit, so add
another 1/3 of 10 to let Jupiter catch up, but now Saturn has gone aroundanother
tenth, so add another tenth of a Jupiter period).. transcendental or something.

The window closes down circa 2015.

There are pretty much always inner planet opportunities, though.

All agog to read the Titan OPAG report when it appears !

...that kind of sucks. As an outsider, I was thinking of overall outer planet programmatic integration (even between national agencies), but I see your point.

Of course, <evil grin>, I wonder what Alan might think about this idea...a mission library might well foster even more productive proposal competition.

(I humbly await my execution for that last...done already fired up a stogie, waiting on the word to put on the blindfold...)

Ralph nails the problem of deciding the next Flagship mission. Titan is by far the most interesting single moon -- and possibly the most interesting planet-sized body, although Mars offers competition -- in the solar system after our own world. (Don't get me started on the lack of new missions to study our own planet. I'm expecting to have to rely on data from European, Indian, etc. craft for my research in a few years.) On the other hand, Jovian-class worlds appear to be common throughout the galaxy (although the sampling is biased because they are easier to detect). The Jovian moons also offer a wealth of diversity and because they lack an atmosphere that reworks their surfaces, you can untangle the geology more easily than at Titan.

So the Jovian system deserves a thorough study with a craft that has modern instruments (a working antenna would be good, too ). Titan deserves study with multiple probes that Ralph mentions. I want both!

In my former life, one of my jobs was to plan product lines -- how to get 50 kg of products with a 35 kg investment. I really want to take Ralph out for a beer and bat around a bunch of ideas.

In some previous posts I listed the resolutions of different camera options for JSO and EE along with some other missions. Since then, I've looked up New Horizon's LORRI's specs, and they are essentially the same in terms of resolution as for EE's proposed narrow angle camera. That class of camera seems to be fine for flybys. It gives decent resolution for studying Jupiter's atmosphere. What it lacks is the ability to carryout good monitoring from a distance of Io. You get okay monitoring, but not great.

Whoever has to decide between these two sets of missions -- Jovian system vs. Titan -- is going to have it tough.

Sounds like you're asking for a super computer project -- like finding all the prime numbers.

Or a distributed computing project like SETI@Home?

Doug had that honor (or was it the other way around?) at Europlanet - he can
attest as to whether it was a good use of his time...


That's why they pay Alan the big bucks, right...

As for the Titan Flagship report - I wish I knew when it will be out - indeed having bust a
gut to write large parts of it over the summer, I wish it were out already. It needs someone to
take out ITAR sensitive stuff e.g. related to the ASRGs, commercially-proprietary data
related to the airbag system on the lander, and APL- and JPL-sensitive cost data.

Editing a public version of the report was not in the original study contract so I think
this awaits some NASA-APL negotiation.
Above my pay grade, sadly.

Thanks for the news on this. Can we take it that it's just the public version that's delayed, and the people who most need to see it have already got the full deal?

I guess the rest of us must be patient. We can always dream about what might be inside those airbags.

You are probably confusing Flandro for the Italian pioneer Gaetano Crocco, who used the name "Grand Tour" for his manned one-year Earth-Mars-Venus-Earth gravity-assist trip. When Flandro presented his results to his boss at JPL he remembered Crocco's work and called the multi-planet opportunity "Grand Tour".